Wavelength Division Multiplexing (WDM) refers to an optical transmission technology of simultaneously transmitting a plurality of optical signals of different wavelengths on one optical fiber. As network bandwidth requirements increase, a WDM system has a broad application prospect. A main component of the WDM system includes an optical add/drop multiplexing (OADM) node, and a function of the OADM node may selectively detaching (dropping) one or more wavelength channels from an optical transmission path and inserting (adding) one or more wavelength channels onto the optical transmission path without affecting optical signal transmission on another irrelevant wavelength channel.
Currently, each OADM node in the WDM system is non-reconfigurable, that is, a route of each OADM node is fixed, and only one or more fixed wavelength channels can be added or dropped. In such a WDM system, each OADM node needs to use, according to initial wavelength allocation, a transmitter, an optical add/drop multiplexer, and an optical multiplexer/a demultiplexer (MUX/DEMUX) of a specific corresponding wavelength. Connection relationships of these optical devices used by an OADM node are also related to the wavelength.
However, after such a non-reconfigurable OADM node is deployed, it is difficult to change the wavelength, and the OADM node has poor network resilience and flexibility. In addition, different OADM nodes need to use different transmitters, optical add/drop multiplexers, and optical multiplexers/demultiplexers. This results in difficulty and costs in WDM system design and deployment, hardware installation, management and maintenance, and the like.